@agentorangeii that does not sound like the mechanical button but it sounds like an issue with the power button flex (it does also connect the audio buttons). I would start by replacing that. Since iFixit does not yet have a specific guide for that use something like this video Replacement flex cables are widely available at many online stores.
While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has a device with the same issues as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.
Repair is War on Entropy!
crwdns2934105:0crwdne2934105:0
crwdns2934113:0crwdne2934113:0
crwdns2915270:0crwdne2915270:0
crwdns2889612:0crwdne2889612:0
1